Dead Pixel Test: Check Your Monitor for Stuck Pixels

Dead, stuck and hot pixels, what's the difference?

Check any screen for dead, stuck and hot pixels by filling it edge-to-edge with pure solid colors. Cycle through white, black, red, green, blue and more in true fullscreen, use the gradient screen to spot colour banding and backlight bleed, and run the built-in stuck-pixel fixer, a rapid RGB flicker that can massage a stuck pixel back to life. Everything runs locally in your browser; no images are uploaded.

A dead pixel is permanently off: it stays black on every background because its transistor gets no power, and it's usually a physical fault that can't be fixed. A stuck pixel is the opposite, one sub-pixel (red, green or blue) is jammed on, so you see a small coloured dot that doesn't change with the image behind it. A hot pixel stays fully lit (white) all the time. The fastest way to tell them apart is to flood the screen with pure colors: a dead pixel is obvious on a white screen, while a stuck or hot pixel jumps out against black. This tool fills your display edge-to-edge with each color in true fullscreen so nothing on the panel is hidden behind browser toolbars.

Features

True fullscreen solid-color cycling through 11 colors (white, black, red, green, blue, cyan, magenta, yellow and three grays) using the native Fullscreen API, no browser chrome to hide faults.
Stuck-pixel fixer that flashes rapid full-saturation RGB noise across the screen with an elapsed timer, the standard technique for reviving a stuck sub-pixel.
Gradient / banding screen: a smooth black-to-white ramp that reveals 8-bit colour banding, panel clouding and backlight bleed.
One-tap color jump grid plus keyboard and click/tap navigation (arrows, space, click to advance).
Auto-cycle mode that steps through every color hands-free at a steady interval.
Auto-hiding on-screen HUD so nothing obscures the pixels you're inspecting.
Works on any device, desktop monitor, laptop, phone, tablet or TV browser, and uploads nothing.

How to use Dead Pixel Test

1
Clean your screen first
Wipe the display with a soft, dry cloth. A speck of dust or a smudge looks exactly like a dead pixel, so this avoids false alarms.
2
Start the color test
Tap 'Start color test' to go fullscreen, then click, tap or press the arrow keys / space to step through each solid color. Turn on Auto to cycle hands-free.
3
Inspect every color closely
Look over the whole screen on each color, ideally in a dark room and straight on. A dead pixel stays black on every color; a stuck pixel shows a fixed red, green or blue dot; a hot pixel stays bright white.
4
Check for banding and bleed
Run the Gradient screen to spot colour banding (visible steps instead of a smooth ramp), and use the black screen to check the edges for backlight bleed or clouding.
5
Try the stuck-pixel fixer
If you find a stuck pixel, run the fixer over it for 10-30 minutes. The rapid RGB flicker can coax the sub-pixel back into working. Gently massaging the spot with a soft cloth while it runs sometimes helps.
6
Exit anytime
Press Esc or tap the exit button to leave fullscreen. Nothing is saved or uploaded.

Common use cases

Inspecting a brand-new monitor, laptop, phone or TV for panel defects within the return window
Checking a used or refurbished screen before buying it
Diagnosing a single bright or dark dot you've noticed on your display
Attempting to revive a stuck pixel with the RGB flashing fixer
Spotting colour banding, backlight bleed or clouding on a panel

Detailed guide

How the stuck-pixel fixer works

Stuck pixels often respond to being rapidly driven through their full colour range. The fixer draws fast, full-saturation RGB noise over the screen, forcing every sub-pixel to switch on and off many times a second, the digital equivalent of exercising a jammed muscle. Run it over the affected area for anywhere from ten minutes to half an hour; stubborn pixels sometimes need a few sessions. A gentle massage of the exact spot with a soft, slightly damp cloth (screen off) while the flicker runs can improve the odds. It's not guaranteed, truly dead pixels won't respond, but it's a free, non-invasive first step before considering a warranty claim.

Beyond pixels: banding, bleed and clouding

The same solid-color screens reveal panel quality issues that a normal desktop hides. The gradient screen shows colour banding, visible bands or steps instead of a smooth transition, which points to a lower-bit-depth panel or aggressive compression. A full-black screen in a dark room exposes backlight bleed (bright patches at the edges) and clouding (uneven greyish blotches), both common on LCD panels. Solid grey and white help spot uniformity problems and yellowing. Because everything is drawn locally in your browser at your screen's native resolution, what you see is your panel's real behaviour, not an artefact of any upload or compression.

How to check a monitor or laptop for dead pixels

Wipe the screen with a dry microfibre cloth first so dust isn't mistaken for a faulty pixel. Open the test in fullscreen, then step through the solid colours with the arrow keys or Space: black, white, red, green and blue. Look slowly across the whole panel from about 30 to 50 cm away. On white and coloured screens a dead pixel shows as a black dot; on black, a stuck or hot pixel glows as a coloured or white dot. On a laptop, turn brightness up to maximum; on an external monitor, switch off dynamic contrast. If you find a coloured dot, run the stuck-pixel fixer over it for 10 to 30 minutes. A dot that stays black on every colour is usually a hardware fault, so check the manufacturer's dead-pixel warranty policy.

Frequently asked questions

How do I test my screen for dead pixels?

Click 'Start color test' to fill your screen with pure solid colors in fullscreen, then step through each one and look carefully over the whole display. A dead pixel shows as a dot that stays black on every color; a stuck pixel shows a fixed red, green or blue dot; a hot pixel stays white. Clean the screen first so dust isn't mistaken for a fault.

What is the difference between a dead pixel and a stuck pixel?

A dead pixel receives no power and stays permanently black on all colors, it usually can't be fixed. A stuck pixel has one sub-pixel jammed on, so you see a small red, green or blue dot that doesn't change with the image. Stuck pixels often respond to the RGB flashing fixer, so it's worth trying before assuming the worst.

Can this actually fix a stuck pixel?

Sometimes. The stuck-pixel fixer flashes rapid full-saturation RGB noise, which can drive a jammed sub-pixel back into working order. Run it over the affected spot for 10-30 minutes, and gently massaging the area with a soft cloth can help. It works on many stuck pixels but cannot revive a truly dead one.

Does the dead pixel test work on a phone or TV?

Yes. It works in any modern browser, phone, tablet, laptop, desktop monitor or a smart-TV browser. On touchscreens you tap to advance through the colors. Fullscreen fills the whole panel so you can inspect every corner.

Why should I clean my screen before testing?

Dust specks, smudges and fingerprints look almost identical to dead or stuck pixels against a solid color. Wiping the screen with a soft, dry cloth first prevents false positives, so anything that remains is a genuine pixel fault.

Is anything from my screen uploaded?

No. Every color and the pixel fixer are drawn entirely in your browser. No screenshots, images or data ever leave your device, the test is completely private.

What is the gradient / banding test for?

The gradient screen shows a smooth black-to-white ramp. If you see distinct bands or steps rather than a seamless transition, your panel is showing colour banding, which indicates a lower-bit-depth display or heavy image compression. The black screen also reveals backlight bleed and clouding at the edges.

How do I check my screen for dead or stuck pixels?

Run the test full screen and cycle through solid colors (white, black, red, green, blue). Any dot that stays the wrong color is a defect; a permanently dark dot is a dead pixel, a fixed-color dot is a stuck pixel.

Can I fix a stuck pixel?

Sometimes. The built-in fixer flashes red, green and blue quickly over the area to try to work the sub-pixels loose. Run it for several minutes; dead (black) pixels usually cannot be fixed.

Dead Pixel Test

Dead, stuck and hot pixels, what's the difference?

Features

How to use Dead Pixel Test

Clean your screen first

Start the color test

Inspect every color closely

Check for banding and bleed

Try the stuck-pixel fixer

Exit anytime

Common use cases

Detailed guide

How the stuck-pixel fixer works

Beyond pixels: banding, bleed and clouding

How to check a monitor or laptop for dead pixels

Frequently asked questions

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Dead, stuck and hot pixels, what's the difference?

Features

How to use Dead Pixel Test

Clean your screen first

Start the color test

Inspect every color closely

Check for banding and bleed

Try the stuck-pixel fixer

Exit anytime

Common use cases

Detailed guide

How the stuck-pixel fixer works

Beyond pixels: banding, bleed and clouding

How to check a monitor or laptop for dead pixels

Frequently asked questions

Related tools

From the journal

How to Remove EXIF Metadata From Your Photos

What Is CPS? How to Test and Improve Your Click Speed

How to Merge PDF Files for Free (Without Uploading Them)